1. Field of the Invention
The present invention relates to an information display system, an information display method, and a computer program product.
2. Description of the Related Art
Electronic filing devices are known in the art that digitalizes paper documents using a scanner. In recent years, ease-of-handling and convenience of such devices have been receiving recognition in the common offices because of availability of low-cost scanners, popularity of multifunction products (MFPs) providing a scanning function, and legislation of the e-Document Law. As a result, instances in which paper documents are scanned and digitalized are increasing. Uses for image databases (DB) are also increasing. An image DB organizes digitalized document image data and photographic image data, as well as document data created using a personal computer (PC) application and the like, in a DB and collectively manages the pieces of data. Even when, for example, an original copy of a paper document is required to be stored, an image DB may be constructed because the image DB facilitates data management and retrieval.
Various image DB are constructed, ranging from a large-scale DB provided in a server device and accessed by a large number of people to a personal-use DB constructed within an individual PC. MFP of recent years include a function for storing documents in an internal hard disk drive (HDD). In some instances, the image DB is constructed based on the MFP.
To view an image within an image DB storing therein a plurality of images, a user retrieves the image to be viewed using an image retrieval method. In other words, when the user knows an image name (file name) of an image to be retrieved, the image is retrieved from a list of image names. However, a displayed thumbnail list is commonly used. For example, when a document image is retrieved, a keyword search is performed and a thumbnail list of candidate images matching the keyword is displayed. The user then selects the image to be retrieved from the thumbnail list. Alternatively, only a thumbnail list of images is displayed from the start, and the user selects the image to be retrieved from the thumbnail list.
A thumbnail list is a cluster of a plurality of minified images displayed in a certain manner on a screen. The user can easily understand contents of the original images from the minified images. In general, the resolution of the thumbnail images in the thumbnail list is reduced to allow simultaneous display of many thumbnail images in a limited area. When a photographic image is displayed in the thumbnail list, the user can understand a content of the photographic image with relative ease, even when the resolution of the thumbnail image is reduced. However, when the image to be displayed is a document image that is mainly text, the user has difficulty reading the text and understanding a content of the document image because the resolution of the thumbnail image is reduced. Therefore, when the user retrieves a document image such as this, the user is often required to display an enlarged view of each document image using a function, such as a viewer, to check the content of the document image. Operability during retrieval is extremely poor. Moreover, particularly in a client-server system using a network, high-resolution image data is required to be newly transferred whenever the user displays an image using the viewer. As a result, a large amount of processing time is required when the user checks a large number of images. Retrieval efficiency deteriorates significantly.
More processing time is required if a large number of thumbnail images are to be displayed in the thumbnail list. Therefore, particularly in the client-server system using the network, waiting time required until the thumbnail images are displayed is shortened by a number of thumbnail images simultaneously displayed in the thumbnail list being reduced. A screen displaying the thumbnail list is changed in a manner similar to that of turning a page. However, because only a small number of thumbnail images can be displayed on one screen, the user is required to turn the page (change the screen) many times. Moreover, the user cannot easily understand the whole aspect of the listed thumbnail images. Therefore, it is not rare for the user to be unable to find a desired image even after viewing all of the pages. As a result, retrieval efficiency further deteriorates.
When the images stored in the image DB are displayed in the thumbnail list, the thumbnail images are not dynamically created from original images stored in the image DB nor is original image data used as is every time the thumbnail list is displayed, namely every time a thumbnail list display screen is created. In general, the thumbnail images that are minified versions of the original images are stored (collected) in the image DB in advance, and the stored thumbnail images are used. Using the stored thumbnail images is advantageous in terms of processing speed. For example, when the thumbnail list display screen is created using HyperText Markup Language (HTML) and the like in the client-server system, the server does not ordinarily create a display screen in bitmap format. The server only creates an HTML document including links to image (file) names to be displayed. The client renders the HTML document using browser software and generates a bitmap-format display screen. In this case, the server is required to transfer all thumbnail images displayed on the display screen to the client, regardless of the image size of the thumbnail images on the display screen (ordinarily specified by the server). Ordinarily, all images are transferred even when some of the images run over an edge of the display screen. Therefore, when the number of thumbnail images displayed on a one screen increases, volume of data required to be transferred also increases. Moreover, because a small volume of data is transferred many times, data transfer efficiency decreases, requiring time for the screen to be displayed on the client end. A packet length during data transfer is ordinarily fixed. Different files are not included in a single packet. Therefore, when small files are transferred, redundant transfer data is generated. When the number of small files to be transferred increases, the pieces of redundant transfer data become difficult to ignore. As a result, transfer efficiency deteriorates. Generally, when the number of thumbnail images to be displayed increases, load placed on the server, such as that involving disk access, also increases.
To solve the above-described problems, a retrieval method in Japanese Patent Application Laid-open No. 2004-25883.8 has been proposed. In the retrieval method, a desired piece of information can be retrieved through a simple operation including a map displaying procedure and a detailed thumbnail displaying procedure. In other words, thumbnail images are disposed on a two-dimensional map, and the thumbnail images are displayed. When a user specifies a point within a certain small area, among a plurality of small areas into which the map is divided, a group of small areas centering around the specified small area is designated as an area to be enlarged. The thumbnail images disposed within the area to be enlarged are enlarged. Contents of the thumbnail images are displayed in detail.
However, in the method in Japanese Patent Application Laid-open No. 2004-258838, a binary display switching is performed that switches between a thumbnail display and a detailed display. Therefore, when the user does not know a position of the image to be retrieved on the map in the thumbnail display, the user may be required to switch to the enlarged display and search thoroughly for the image to be retrieved. Magnification may also be insufficient in the enlarged display. When the number of thumbnail images displayed on the map during the thumbnail display increases, the image size of the thumbnail images decreases because the thumbnail images cannot be displayed so as to overlap. The thumbnail list may become incomprehensible. Moreover, when the number of thumbnail images displayed on the map increases, time may be required to display the images, as described above.